CHICAGO – Chrysler’s all-new fifth-generation ’13 SRT Viper high-performance sports car went on sale in November, and it didn’t take long for the first 800 units to sell out. Customers will start receiving their cars next month.

Brisk demand for the 640-hp 2-seater comes despite a completely new approach to rolling out the car that became an instant halo not only for Dodge but the entire Chrysler group when it came to market in 1995.

For the first time, the Viper isn’t launching initially as a convertible. Four previous generations of the car went on sale as a droptop, to be followed later by fixed-top coupes. This time, the cycle is reversed.

In 2003, it took four years for the hardtop to join the convertible lineup. “We won’t wait that long” to begin selling a convertible version of the new Viper, says Ralph Gilles, president of Chrysler’s SRT performance division, on the floor of the auto show here.

Asked how long it will take for the convertible to arrive, Gilles tells WardsAuto he hopes within a few years.

When the time comes, Gilles says removing the top will be simple. “The car was designed to be a convertible,” he says. “Under the skin is a convertible chassis. It’s already there – the stiffness is there. It’s extremely easy should that come, but we’re not in any rush.”

To enthusiasts of the V10-powered hand-built Viper, the launch sequence is not a big deal. “I get a lot of comments from them, and a lot of them love the car either way,” Gilles says.

“Some of them will buy (the coupe), and then when the convertible comes out, buy another one, or switch. And a handful of them say, ‘I’ll wait for the convertible.’”

When the fourth-generation Viper ended its production run in 2010 at Detroit’s Conner Avenue assembly plant, the mix was about 60% hardtops and 40% convertibles.

The development team working on the Viper considered launching the car first as a convertible but then decided on the hardtop so the car could qualify for ALMS racing events.

That strategy paid off recently when Chrysler scored an invitation from the Automobile Club de l’Ouest to run two SRT Viper GTS-Rs in the LM GTE Pro class of the 2013 24 Hours of Le Mans in France June 22-23.

“We’re very excited about that,” Gilles says.

The Viper finished one-two in the GTS class competition three consecutive years – from 1998 to 2000 – and has not participated in the race since.

Testing of the Le Mans race car began Feb. 7 at Sebring International Raceway in Florida.

Based on the take rate of the first 800 vehicles, Gilles says more than 80% of Viper buyers are opting for the GTS version, which starts at $120,395, has a more upscale leather interior and weighs an extra 100 lbs. (45 kg) due to the addition of a 2-mode suspension and extra sound deadening.

The remaining share of the first production run will be base models, which start at $97,395. Both prices exclude $1,995 destination charges. Gilles says Chrysler initially planned 70% of initial sales to be GTS.

“I’m very proud we can do the SRT at that price point,” he says. “I can’t think of another car on the planet that powerful and fast, capable of 206 mph (332 km/h) and under $100,000.”

The new Viper uses carbon fiber for the hood, roof and decklid, while doors are made of super-formed aluminum. Reaction-injection molded plastic is used for the front and rear fascia and rear fenders. Much of the previous Viper’s body consisted of sheet-molded composite.

Gilles says the body panels of the new car are fitting well, even though three different materials are integrated.

“Look carefully at the split lines of the car – we designed it so it’s forgiving,” he says. “RIM actually expands a little bit under heat. Carbon fiber and aluminum are stable. We’ve been dealing with fascia expansion in production cars ever since fascias came around. Even the best materials grow a little bit under heat.”

Gilles says he is glad General Motors is launching an all-new Chevrolet Corvette, although he does not consider it a direct competitor because it sells in higher volume, achieving 14,132 deliveries in 2012, according to WardsAuto data.

“We’ll never do more than 2,000 units a year,” he says of Viper.

But every hero needs a foe, Gilles says. “Corvette allows Viper to exist, and vice versa. But I think they are very different cars. We are very low volume, race-special, bespoke, more exotic in a way than Corvette is.”

Gilles says he believes the new Viper will be more marketable to a global audience than the previous version because the auto maker has set a “much higher standard for its execution,” especially for interior comfort and design.

“I would put that interior up against anyone in the world,” he says. “The fit-and-finish is on par with the very best. I’m including Aston Martin in this,” as well as the Porsche 911.

European-spec Vipers are not yet ready for sale, but he knows the car will be popular in Europe, where private Viper clubs already exist in Sweden, Germany and the U.K.

“I’m going to visit them this summer, going to hang out with Viper clubs in Europe,” he says.

Chrysler began developing the new car shortly after exiting bankruptcy in summer 2009, which is when Scott Krugger got the job as lead exterior designer.

“The hardest part was maintaining the purity of the Viper,” Krugger says. “Ten years from now, we want the Viper to look as great as it does now.”

tmurphy@wardsauto.com